IPv6 adoption across government web infrastructure remains uneven around the world. We decided to measure it across the United States, and the story turned out to be far richer than a single number suggests. Part of the reason is that the US government’s internet infrastructure has a structural advantage that makes this kind of analysis unusually powerful.
A unified namespace for all of government
Most countries fragment their government presence across multiple TLDs by tier. India, for example, has .gov.in for central government and .nic.in for the National Informatics Centre. Many countries also keep separate domains for states, counties, and municipalities.
The United States took a different path. Since 2021, CISA (the Cybersecurity and Infrastructure Security Agency) has managed .gov as a unified TLD open to all US government entities at every level. Today, a single .gov query captures:
- Federal agencies:
irs.gov,nasa.gov,cdc.gov,ai.gov - State agencies:
alabamapublichealth.gov,alaskacapitol.gov,akleg.gov - County governments:
adamscountyco.gov,alamancecountync.gov - Cities and municipalities:
aberdeenmd.gov,abilenetx.gov,amarillo.gov - Fire districts:
altavillemelonesfpd.gov - Courts:
13thjudicialil.gov,35thdistrictcourtmi.gov - Tribal nations:
absenteeshawneetribe-nsn.gov - School districts:
alpineschoolsca.gov
This means we can measure IPv6 adoption across the entire American government, every layer and every jurisdiction, with a single dataset.
The headline number: 20.4%
Of the 13,338 .gov domains we track with an IPv4 (A) record, 2,725 also have an IPv6 (AAAA) record, a 20.4% adoption rate.
But averages hide the most interesting parts.
Which tier of government is leading?
When we break .gov down by government type, using domain patterns like -nsn.gov for tribal nations, county for county governments, state abbreviation suffixes for cities, and regex matching for courts, the picture fragments in surprising ways:
| Government tier | Domains | IPv6 | Rate |
|---|---|---|---|
| Federal & Other | 3,990 | 1,083 | 27.1% |
| Courts & Judiciary | 97 | 26 | 26.8% |
| Fire Districts | 200 | 45 | 22.5% |
| School Districts | 48 | 10 | 20.8% |
| State Agencies | 7,132 | 1,261 | 17.7% |
| County Government | 1,702 | 284 | 16.7% |
| Tribal Nations | 169 | 13 | 7.7% |
Courts beat state agencies. Federal courts and judicial circuits sit at 26.8%, above every other tier except the federal government itself. Whether this reflects better IT procurement or simply smaller web footprints that are easier to migrate, we cannot say. It is a notable outlier either way.
Fire districts are ahead of county government. This one was surprising. Individual fire protection districts, often small and locally operated, are at 22.5%, beating both state agencies and county governments. One likely explanation is that many fire districts have recently moved their small websites to modern managed hosting platforms that default to IPv6, whereas larger county government sites sit on older, self-managed infrastructure.
Tribal nations are the most underserved. At 7.7%, tribal nation .gov domains sit at the bottom of every civilian tier. This reflects a broader digital infrastructure gap, since many tribal nations operate with limited IT resources and older hosting infrastructure.
The military paradox
.mil, the top-level domain for the US military, is tracked separately. The numbers are striking for the wrong reason.
Of 160 .mil domains we track, only 7 have IPv6, a rate of 4.4%. The US military, responsible for some of the world’s most sophisticated technology, has a lower IPv6 adoption rate on its public-facing websites than nearly every civilian tier of US government. The DoD has mandated IPv6 adoption internally since 2003, but the public web footprint tells a very different story.
Which states are leading, and which are falling behind?
We can extract a 2-letter state code from the end of most local government .gov domains, so aberdeenmd.gov maps to Maryland and abilenetx.gov maps to Texas. This lets us rank states by the IPv6 adoption rate of their city, county, and state agency web presence.
Top performers:
| State | Domains | IPv6 | Rate |
|---|---|---|---|
| Wisconsin | 578 | 190 | 32.9% |
| Utah | 107 | 35 | 32.7% |
| Florida | 195 | 59 | 30.3% |
| South Carolina | 107 | 32 | 29.9% |
| Arkansas | 160 | 37 | 23.1% |
Lagging:
| State | Domains | IPv6 | Rate |
|---|---|---|---|
| Nebraska | 201 | 16 | 8.0% |
| Virginia | 154 | 13 | 8.4% |
| Georgia | 260 | 25 | 9.6% |
| Tennessee | 218 | 20 | 9.2% |
| Massachusetts | 306 | 30 | 9.8% |
The Virginia paradox deserves its own mention. Ashburn, Virginia is home to more internet exchange capacity than any other location on Earth. The state sits at the heart of US internet infrastructure, and yet its government websites rank near the bottom for IPv6 adoption at just 8.4%. Physical infrastructure and web presence modernisation are clearly decoupled.
Wisconsin leading at 32.9% is harder to explain from the outside. The state’s government IT consolidation efforts in recent years may be a factor.
Cloudflare is responsible for 70.8% of all US government IPv6
When we look at which networks actually serve IPv6 for .gov domains, the picture is stark:
| Provider | IPv6 .gov domains | Type |
|---|---|---|
| Cloudflare | 1,930 | CDN |
| Akamai | 195 | CDN |
| Amazon AWS | 170 | Cloud |
| Fastly | 104 | CDN |
| US Treasury (own infra) | 38 | Government |
| US DOJ (own infra) | 14 | Government |
| US Interior (own infra) | 14 | Government |
CDNs and cloud providers account for 88% of all IPv6-capable .gov domains. Government-run infrastructure, meaning the agencies that operate their own AS numbers and data centres, accounts for just 2.4%.
The pattern is clear. CDN-fronted sites are the primary driver of IPv6 adoption in government web presence. When Cloudflare rolls out IPv6 by default on its edge network, every government customer gets it automatically. The remaining 80% of .gov sites, the ones on self-managed hosting, are largely still IPv4-only.
Methodology
Data sources: IPv4 domain data from IPinfo’s ip_hosted_domains table, which maps IP addresses to domains observed serving traffic. IPv6 data from aaaa_hosted_domains, the equivalent for AAAA records. ASN attribution via BGP prefix data (prefix_details), matched to operator names via WHOIS records.
Government tier classification: Rule-based regex matching on domain labels:
- Tribal: domains containing
-nsn - County: domains containing
county - Courts: domains containing
court,judicial,circuit, orappeals - Fire districts: domains containing
fire,fd., orfiredistrict - Cities/municipalities: domains whose second-level label ends in a two-letter US state abbreviation
- State agencies: domains with a state abbreviation directly before
.gov - Remaining: classified as Federal & Other
State code extraction: Regex applied to the end of the second-level domain label (e.g., abilenetx.gov → TX). This method covers city and county websites with state-code suffixes. It undercounts state agency domains that use full state names (e.g., alabamapublichealth.gov).
Anticipated challenges, and our answers
“Your 20.4% number counts subdomains. The ‘real’ number is lower.”
Our data is deduplicated at the domain level, not the subdomain level. So data.cdc.gov and cdc.gov are counted separately if both have AAAA records. This slightly inflates domain counts, but it is consistent between the IPv4 and IPv6 calculations, so the percentage holds.
“Cloudflare uses anycast, so you cannot tell which domains are really IPv6-enabled.”
For this analysis we are asking one thing: does the domain return an AAAA record? If a domain resolves to a Cloudflare IPv6 address, it is reachable over IPv6 by end users, regardless of how the traffic reaches Cloudflare’s origin. The number is real.
“Wisconsin at #1 seems fluky, with a small sample and high variance.”
Wisconsin has 578 government domains in our dataset, which is not a small sample. It is the largest state representation in the dataset after New York (932). The 32.9% rate is statistically meaningful. That said, state rankings may be influenced by a single large web hosting consolidation decision by a state agency, and we cannot rule that out without deeper investigation.
“Your tribal classification based on -nsn will miss some tribes.”
Correct. The -nsn suffix (Native Sovereign Nation) is a common pattern in tribal .gov domains, but not all tribes use it. Our 169-domain count for tribal nations is a lower bound. The 7.7% adoption rate may also be a lower bound, or it may not be, depending on which tribal domains are uncaptured.
“The military .mil comparison is not fair, since those might not be public-facing sites.”
The 160 .mil domains we track all have A records pointing to reachable servers, so by our methodology they are public-facing. The DoD operates well-known public sites like defense.gov, army.mil, navy.mil, and af.mil. The 4.4% IPv6 rate covers this public footprint.
What this tells us
The US government’s 20.4% IPv6 adoption rate looks respectable on its face, but it largely reflects CDN adoption rather than deliberate government infrastructure modernisation. Strip Cloudflare out of the picture and the underlying government-run number falls to around 2 to 3%.
The story is not that the US government is good at IPv6. It is that Cloudflare defaulted to IPv6, and 70% of IPv6-capable government sites came along for the ride. The remaining 80% of .gov sites, the ones on legacy hosting, internal data centres, and infrastructure with no CDN in front of it, are a different picture.
The Tribal Nations number (7.7%) and the military number (4.4%) are the ones worth watching. Both reflect structural gaps that no amount of CDN migration will solve automatically.
